Low-Cost, High-Throughput Process Using HF Acid to Singulate Fused-Silica Shell Resonators with High-Q

In this paper, we report a low-cost, fast, and high-throughput process for releasing molded fused-silica 3D micro-shell resonators from their original flat substrate. 49% Hydrofluoric Acid is used to selectively etch the flat part of the substrate to release the resonator shell. Nine resonators are released using this approach and the quality factor is measured and compared with 22 shells singulated using our standard lap/CMP method. In addition, the frequency mismatch of another four devices released using each method is compared. All the resonators exhibited high-Q (as high as 5.8M) and low frequency mismatch comparable to those processed using lap/CMP method.